Associative performance deficits are frequently attributed to acquisition failure with little empirical justification. Recent demonstrations that restorative treatments (often reminders designed to exclude further acquisition concerning the target information) can reverse many associative performance deficits suggest that these deficits are due to retrieval failure or response competition. Using rats in classical conditioning paradigms due to the high degree of stimulus control afforded, we will continue this research with the ultimate goal of contributing to an information processing model relevant to normative human behavior. Half the proposed research will focus on effects of context. In addition to direct context-US associations and contextual potentiation of retrieval of associations between the nominal CS and US, it appears that context servies as an associative baseline against which an organism evaluates a nominal CS. Prior research on this last issue has confounded training context with test context. We plan to independently vary the associative strength of these two contexts. Preliminary work indicates that the associative strength of the test context is used for comparison with the target CS. Noting that 0 less than or equal to P(US/CS)less than or equal to 1, which suggests that all associations between CSs (including contexts) and USs are neutral or excitatory, the approach leads to the conclusion that conditioned inhibition is not a property of an association, but only the consequence of testing a CS in a context more excitatory than the CS itself.--The other half of the research will use reminder techniques to determine if latent inhibition, one-trial overshadowing, and one-trial blocking can be added to our list of associative performance deficits that do not arise entirely from impaired acquisition. Additional experiments will determine if our recent observation of recovery from multitrial overshadowing and blocking depends equally upon all the reinforced compound trials or only upon the first few; i.e., are overshadowing and blocking on early compound trials an acquisition failure but on later compound trials a retrieval failure? Another series of studies will determine, when A blocks or overshadows X, if recovery of responding to X is the consequence of a direct X-US association or of X-A and A-US associations. We also plan to test Bolles' hypothesis that animals differentiate contiguity from contingency, with both being learned but only the latter controlling behavior.